1. Field of the Invention
The present invention relates to the field of data storage devices. More particularly, the present invention relates to an air bearing slider for use with a read/write head of a disk drive.
2. Description of the Related Art
FIG. 1 shows a high RPM disk drive 10 having a two-stage, or piggy-back, servo system for positioning a magnetic read/write head (or a recording slider) over a selected track on a magnetic disk 11. The two-stage servo system includes a voice-coil motor (VCM) 13 for coarse positioning a read/write head suspension 12 and a microactuator, or micropositioner, for fine positioning the read/write head over the selected track. FIG. 2 shows an enlarged exploded view of the read/write head end of suspension 11. An electrostatic rotary microactuator 14 is attached to a gimbal structure 15 on suspension 12, and a slider 16 is attached to the microactuator. A read/write head 17 is fabricated as part of slider 16.
Air bearing slider designs for a data storage applications, such as the disk drive 10, provide a flying interface between a magnetic head and a magnetic medium recording disk. The interface is cushioned by a thin layer of air that prevents excessive, undesirable head/disk contacts that can cause damage to the head or the disk. The air bearing force that acts to maintain the head/disk spacing, however, is influenced by the atmospheric pressure. As the atmospheric pressure decreases, such as when a disk drive is used at an altitude above sea level, the flying height of the air bearing slider usually decreases and unwanted head/disk contacts may occur. In the situation when the flying height of the air bearing slider increases as the atmospheric pressure decreases, the magnetic read head may lose signal amplitude, therefore rendering the disk drive non-functional.
It has always been a primary design objective to minimize the altitude flying height change of a magnetic element on an air bearing slider as a function of atmospheric pressure. Conventional positive-pressure air bearing designs have a large altitude sensitivity. Conventional negative-pressure air bearing designs have improved the altitude sensitivity of sliders, but have not totally eliminating the effect.
What is needed is an air bearing slider that is virtually altitude insensitive, and is applicable to both positive- and negative-pressure air bearing types.